Vitamin-D Toxicity And Other Non-Malignant Causes Of Hypercalcemia: A Retrospective Study At A Tertiary Care Hospital In Pakistan.
J Ayub Med Coll Abbottabad. 2017 Jul-Sep;29(3):436-440.
Khan MN1, Masood MQ2, Siddiqui MA3, Naz S2, Islam N2.
- Loading dose of Vitamin D to restore vitamin D levels in most of the world are typically a single dose of 400,000 IU (range 200,000 to 600,000)
- Overview Loading of vitamin D
- 600,000 vitamin D loading doses – good response to both oral and muscular – Oct 2015 has the following
|600,000 IU IM||94%||30 ng|
|600,000 IU oral||83%||20 ng|
|200,000 IU IM||88%||18 ng|
|200,000 IU oral||71%||14 ng|
- Overview Toxicity of vitamin D has the following chart, based on 20+ studies
- “In most of this overenthusiastic practice of Vitamin-D replacement D3 600,000 IU injection given weekly for 6-8 weeks.”
- “Considering this overenthusiastic practice of Vitamin-D replacement we recently have published a randomized control trial comparing replacement strategies with oral and intramuscular doses of commonly used preparations. Our study showed that a single dose of 600,000 units of Vitamin-D3 corrected the VDD in 94% of the participants and multiple injections were not required to correct the VDD. 5 “
Hypercalcemia is a common clinical problem; primary hyperparathyroidism and malignancy is commonest causes of hypercalcemia. Aetiology of hypercalcemia are changing, causes that were diseases of the past like Vitamin-D toxicity and milk alkali syndrome are observed more often. Vitamin-D deficiency is an important problem and overzealous replacement of Vitamin-D has been observed, suspected to cause toxicity.
This was a retrospective review of patients admitted at the Aga Khan University Hospital from January 2008 to December 2013 with hypercalcemia. We reviewed the electronic health records for laboratory and radiological studies, and discharge summaries to establish the cause of hypercalcemia. Patients with solid tumour malignancy were excluded from the analysis. The treatment records and hospital course of patients diagnosed with Vitamin-D toxicity were also reviewed.
Primary hyperparathyroidism was the most common cause of hypercalcemia comprising 41 (28.2 %) patients. Vitamin-D toxicity was present in 25 (17.3%) and probable Vitamin-D toxicity 11 (7.6 %) inpatients. Vitamin-D toxicity and probable Vitamin-D toxicity together comprised 36 (24.8%) cases. Other causes of hypercalcemia included multiple myeloma 18 (12.4%) patients, tuberculosis 6 (4.1%) patients, chronic kidney disease 6 (4.1%) cases, sarcoidosis 4 (2.7%) and lymphoma 3 (2.0%) patients. In 29(20%) patients a cause of hypercalcemia could not be determined and were labeled as undiagnosed cases.
Vitamin-D toxicity was the second commonest cause of hypercalcemia after primary hyperparathyroidism. Knowledge of the prevalent and emerging causes of hypercalcemia is important for prompt diagnosis and treatment..